Method of die rolling



pa e July 29,1924.

m'nzo STATES PATENT OFFICE.

wILL P. wrrrrnaow, or rrrrsnunen, rnNNs'YLvANm, assrcnon To wrrnnaow STEEL COMPANY, or NEVILLE ISLAND, rENNsY vmA, A CORPORATION or PENNSYLVANIA.

METHOD or DIE ROLLING.

No Drawing.

To all whom it my concem:

Be it known that I, WILLIAM P. WITH- nnow, a citizen of the United States, residing at Pittsburgh, in the county of Alle- 5 gheny and State of Pennsylvania, have in- At the present time, considerable diifi culty is encountered in the die rolling art in 'the production of finished articles or blanks having accurate and uniform dimen- 1'1 sions. Many attempts have been made to produce blanks for certain purposes, but

due to the variations in the dimensions many of these attempts have been abandoned. i

Inthe metal rolling ,art, other than dierolling, it is custoriia to produce variations in the dimensions of rolled articles by changing the temperature of the ingot being rolled, the temperature being increased wh en it is desired to increase the dimensions of-the article. By increasing the temperature it is not unlikely that increased dimensions are insured due to the fact that the ease of flow of the, metal underthe action of the rolls is increased;-

.By continued investigation and repeated the reductions of the leader throughout its length may vary to produce the blanks, I have found that in order to .increase the length of a die rolled blank the reverse efl'ect occurs, so that it is necessary to decrease the temperature of the billet or leader being rolled, while'to decrease the length of the rolled blank it is essential to increase the temperature oiLthe billet or leader. I have produce a shorter blank than will be prob duced at'the same temperature if the per cent of reduction is decreased.

" experiments in the die rolling art in which of the blank; 7

also found that the variations produced on the billet or leade'rby the die rolls. In-

Applieation filed September 9, 1922. Serial No. 587,080.

In accordance with the present invention, the temperature of the entering material is decreased to produce longer blanks and increased to produce shorter blanks, the variations in the temperature being figured in accordance with the percentage of reduction being eflected by the die rolls. It is believed that these results are accomplished for the reason that as the temperature of the metal is increased the slippage between the rolls and-the metal is increased, thereby resulting in a shorter product; while if the temperature is decreased the effective grip on the metal is increased, thereby subjecting the same to an increased rolling action which eflectsa greater flow of metal and consequently a longer blank. These results ma however, be due to other causes.

11 other words, the process is carried out by noting the temperature at which what might be called test leaders, are pamed throughthe rolls, and such die-rolled blanks are then measured and the necessary corrections for length of the successive dierolled blanks are thenmade bypassing the leaders to the rolls at a lower temperature, than the above mentioned leaders, if longer blanks are desired or at a higher temperature if shorter blanks are desired.

The advantages of the'present invention arise from the method of insuring uniform results in an expeditious manner by merely varying the temperature at which the metal is fed to the die rollsto control the length .prising the step of passing a heated leader at a given temperature through a die-roll pass, and then die-rolling similar blanks. from successive leaders by delivering such leaders tohthe die-rolls at a reduced temperature if longer blanks are desired. 1

2.'The method of die-rolling blanks predetermined length from leaders, comprising the step of passing a heated leader at a given temperature through a die-roll pass, and then die-rolling similar blanks from successive leaders by. delivering such leaders at a higher temperature if shorter blanks are desired.

3. The method of-die-rolling blanks of.

predetermined length from leaders, comprising the step of passing a heated leader die-rolling blanks of at a given temperature through a die-r011 pass, and then die-rolling similar blanks from successive leaders by delivering such leaders to the die-rolls at a reduced temper- 5 ature if longer blanks are desired, such reduction in temperature being in accordance with the percentage of reduction of the blank.

4;. The method of die-rolling blanks of l predetermined length from leaders, comprising the step of passing a heated leader at a given temperature through a die-roll pass, and then die-rolling similar blanks from successive leaders by delivering such leaders at a higher temperature if shorter blanks are desired, such increase in temperature being in accordance with the percentage of reductionof the blank.

In testimony whereof I have hereunto set my hand.

' WILLIAM P. WITHEROW. 

